Discussion Marginally smaller than similar Common Murre. Has shorter, thicker bill (almost gull-like) with striking white stripe along gape. Neck is thicker than Common, and plumage darker overall, although latter feature is often hard to discern in poor light. Adopts upright posture when resting on cliff. Swims well, dives frequently, and flies on whirring wingbeats. Sexes are similar.